Insulating board or slab.



GEORGE KELLY, OF HINSDALE, ILLINOIS.

INSULATING BOARD 0R SLAB.

Specification of Letters Patent.

Patented Nov. 5, 1907.

Application filed June 22, 1906- Serial No. 322.944

To all whom it may concern:

Be it known that I, GEORGE KELLY, a citizen of the United States, residing at Hinsdale, in the county of Dupage and State of Illinois, have invented a new and useful Insulating Board or Slab, of which the fol lowing is a specification.

nary unprinted paper, and that the printed sheets can be made to more closely adhere with a less amount of binding agent than the unprinted sheets. Moreover, as printed sheets become waste material, they can be secured at very small cost, and being of substantially uniform size, the necessity and expense of first cutting them is eliminated.

In carrying out the present invention, a plurality of sheets of printed paper stock, such'as old newspapers, are first moistened or coated by brushing or dampening them with a solution of borax and water, or the like. This has a tendency to soften the inks and prepare a suitable foundation for the adhesive. The moistened sheets are then coated with a suitable cementitious binding agent. While this agent may be of any desired character, it is preferably composed of liquid glass alone, or liquid glass with a mixture of sulfur or the mixture of liquid glass, sulfur and rubber in about the proportions set forth in co-pending application, Serial No. 313,427. The sheets are then laid one upon the other and are pressed closely together by any suitable means. The result is an exceedingly strong and very durable article of manufacture that has excellent insulating qualities, particularly when the liquid glass is employed.

The use of old newspapers and similar sheets having printers ink thereon is an exceedingly important feature of the present invention, in connection with the ingredients and the steps of the process set forth. As is well known, printers inks are made up of a fat or grease combined with carbon and like substances. Experience has demonstrated that the alkali applied to the sheets not only softens and spreads the ink, but 1 cuts the fat or grease so that the remaining ingredients produce an excellent'foundation, and the silicate of above. better foundation for cementitious binders than ordisodium will adhere more successfully. Moreover it has been demonstrated that a very much less amount of the binding agent is required in securing these printed sheets than in securing plain unprinted sheets. A further advantage resides in the fact that the sheets are all of the proper size to be treated without the necessity of cutting them, thereby saving considerable time and expense. As already stated, the slab or board thus produced is particularly useful for electrical insulating purposes, but can be employed in other relations. In case it is desired to cover the printed sheets, facing sheets of unprinted material may be applied to the opposite sides of the body produced as These unprinted sheets while applicable to the printed sheets, require considerably more of the binding agent to cause them to properly adhere.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is:

1. The method of manufacturing insulating boards and the like. which consists in applying to sheets having printers ink thereon, an alkali and cementing said sheets to gether.

2. The method of manufacturing insulating boards and the like. which consists in applying to sheets having printers ink thereon, a solution of borax and water that cuts the grease in saiddnk, and afterwards cementing said sheets together with liquid glass.

3. The method of manufacturing insulating boards and the like, which consists in employing a plurality of sheets having printers ink thereon, cuttmg the grease in the ink, applying a binding agent to thesheets, and cementing said sheets together with said binding agent.

4. The method of manufacturing insulating boards and the like. which consists in employing a plurality of sheets of paper of substantially the same size having printers ink thereon, cutting the grease in the ink on said sheets by applying borax and water thereto, and cementing said sheets together.with liquid glass. I

5. As an article of manufacture, a body comprising a plurality of sheets of material having printers ink there- GEORGE KELLY.

Witnesses L. C. WELCH, GEO. W. HALLJ 

